Thomas l



Feb. 3, 1931. 'r. L. MURPHY T VALVE CHEST FOR-ROCK DRILLS Filed May 17. 1928 2% #17 111? 7 0112a 1450 BY duQ/fl" flag Z1075 ATTORNEY Patented Feb. 3, 1931 UNITED STATES PATENT OFFICE 'rnomis L. MURPHY, or EASTON, PENNSYLVANIA, nssienon TO increment-RAND COMPANY, or JERSEY CITY, NEW JERSEY, A 'coRPoaATIoN on NEW JERSEY VALVE CHEST FOR nocx DRILLS Application filed May 17, 1928. Serial Ho. 278,370. I

This invention relates to rock drills, but

more particularly to a valve chest for fluid and 1a cation and in which similar reference charac ters refer to similarparts, I

Figure lis a sectional elevation of somuch of a rock drill as will serve to illustratethe invention,.and

Figures 2 and 3 aretransverse views on the lines 2-2 and 3.3 looking in theldirection'indica'ted by the arrows.

Referring more particularly to the drawings, A designates a cylinder having a free cylinder A controls the free exhaust port B and has a reduced forward extension D adapted to strike against a working implement (not shown). cylinder A isrsealed by a head E having a bore F to slidably receive theextension D. At the rearward end of the cylinder A is a back head G which may be connected to the cylinder bymeansof side rods H. The back head G is provided'with a bore J in' which isdisposed a throttle Valve K' for controlling the admission of pressure fluid into theidrill. The throttle valve K has a bore L'into which pressure fluid from a suitable source of supply (not shown) may be admitted, and in one side of the throttle valve K is a port 0 which in the open position of the throttle valve registers with a passage P leading to a supply chamber Q formed in the contiguous surfaces of the back head G and a plate R interposed between the back head G and the cylinder A. V

Preferably the plate R is provided at its 1 forward end with a projection S which extends into the rearward end of the cylinder taken 7 exhaust port B. A piston C disposed in the The front end of the .7

for the purpose of centralizing said plate withrespect to the cylinder. Theplate R has a; bore T which forms a bearing for a trunnion U of a rifle bar V interlocked slidably with the piston in the usual manner fOIffll'Ilcooperate with a. toothed rotation ratchetfY during the I for .causingrotation of the piston forward stroke of the piston.

' fIn accordance with thepresent invention, 7

a valve chest comprisinga pair'ofplates and b are disposed in the rearward end of the cylinder A to form a valve chamber a."

The plate Z formsa closure for'the rearward.

end of the cylinder and is provided with a pair of inlet passages 5d and e for conveying pressure fluid from the valve chamber 6 to the rearward and forwardends respectively of the c'ylinden. A passage fin the cylinder in this instance forms a, continuation of the passage-e to the front end of the cylinder.

The .plate 6 serves as a seat forthe head W and the rotation ratchet Y and the valve chamberc may be formed as shown by recessing the, forward end of the plate I). In the valve chamber 0. is disposed a distributing valve 9 ofthe oscillatory platetype having a fulcrum h on its transverse median line on which the valve 9 is pivoted.

In the'present instance the valve g is provided with a central aperture y'to receive a hollow pluglc disposed about the rifle bar to prevent leakageof pressurefluid from the valve chamber along the rifle bar into" the rearward end of the cylinder A. The plug 72 has a lateral shoulder 0 which acts as a valve stop and said shoulder 0 preferably lies somewhat below the uppermost surface 10 of the valve chamber so that pressure fluid may flowjfreely over the raised ends of the valve into the inletpassage's. V

In the plate I) is formed an aperture 9 through which the plug is extends. .The aperture 9 is of sufliciently larger diameter. than the plug is to formanannular supply passage 1' through which pressure fluid is admitted into thevalve chamber 0. The am r l .55 parting rotary movement to'theworklng it". i

nular supply passage r communicates with the supply chamber Q through the transverse passages 3, formed in the plate I) and passages 25 and a formed in the rotation ratchet Y and the plate R respectively and lying radially outside of the rifle bar.

In the preferred form of the invention the plate I) is formed with a rearward reduced extension adaptedto seat in a circular recess formed in the adjacent end of the rotation ratchet Y. Peripheral grooves in the reduced extension cooperate with the walls of the recess to form passages 25 which are continuations of the passages t. Thepassages s extendto the periphery of the reduced portion and communicate with the passages-t" adjacent the forward extremities thereof.

The course of the pressure fluid during the operation of the drill is as follows: After the throttle valve K is opened to the position ber will be obviated. This is desirable since it tends to quicken the action of the valve.

I-Ieretofore in drills employing valves of the type illustrated, it has been customary to admit the pressure fluid into the valve chamber over the end or near the end of the valve. The admission of the pressure into the valve chamber in this manner, however, causes the pressure fluid to eddy in the intermediate portion of thevalve chamber and to retard the action of the valve/ Due to the present invention this sluggish action of. the valve has been entirely overcome and the efficiency of the drill is therefore considerably increased.

I claim: r 1 p 1. In a fluid actuated rock drill, the combination of a cylinder and a piston, a valve chest in the cylinder comprising. a pair of plates disposed in face to face relationship andforming a closure for one end of the cylinder, rotation mechanism for the piston including a ratchet ring seated on said valve chest and a rifle bar engaging the ratchet ring and extending through the valve chest to interlockingly engage the piston, a centrally'disposed recess in the face of one of the plates to form a valve chamber, a sealing plug disposed about the rifle bar and cooperating withthe plates to prevent leakage ofpres:

. surefluid fromthe'valve chamber along the rifle bar, inlet passages leading from the valve chamber to the cylinder, an oscillatory plate valve in the valve chamber controlling the inlet passages, said valve having a central bore to receive the sealing plug, a central axial bore in the rearmost plate to form an annular supply passage in the valve chest encircling the sealing plug, longitudinally disposed passages in the ratchet ring and the rear nost plate the last said passages cornmuulcating with a source of pressure fluid the rearmos't plate connecting the last mentioned passages'with the annular supply passage, and-a shoulderon the sealing plug 10- catedbelow the upper wall of the valve chamher to form a stop for the valve.

2. In a fluid actuated rock drill, the combination'of a cylinder and a piston, a valve" chest in the cylindercomprising a pair of plates disposed in face to face relationship and forming a closure for the rearward end of the cylinder, a reduced extension on the rearinost plate, a ratchet ring adapted to seat on the 're'armost plate and having a recess in one end to receive the extension on said plate, a rifle bar engaging the ratchet ring and extending through both platesto inter lockingly engage the piston, a centrally disposed recess in the faceof'one oftheplates to form a valve chamber, a sealing plug "dis posed about the rifle bar. and cooperating with the plates to prevent leakage of pressure fluid from the valve chamber along the. rifle bar, inlet passages leading from the valve chamber to the ends of the cylinder, an

oscillatory plate valve in the valve chamber controlling the inl'et passages, said valve having a central'bore to receive the sealing plug, a'central axial bore inthe-rearmost plate to form an annular supply passage encircling the sealing plug, longitudinally'dis{ posed passages n the ratchet ring communieating with a, source of pressure fluid supply,

peripheral grooves in the extension forming continuations of the last said passages, transversepassages in the extension connecting said' grooves with the annular supplypassage,'and a shoulder on the sealingplug located below the upper wall of the valve chamberzto form a stop for the valve.

In testimony whereof I have signed this specification. M

THOMAS LLMURPHYQ 75 supply, transversely extending passages 1n 

